Your soup or stew is thin and you’d like it have a richer consistency but don’t want to deal with the lumpiness of trying to thicken the pot at this stage of cooking.
Ever add a tablespoon or so of flour to a pot of stew to thicken it only to have lumpy balls of gummy goo swimming in your pot? Do as the chefs do and mix up equal parts soft butter and flour. About one tablespoon of flour thickens one cup so do the math and figure out how much you’ll need. Then whisk in the butter paste by the teaspoonful as your pot simmers. This technique adds thickening power (flour) and richness (butter). Always a tasty move.